Low-affinity antibodies against collagen type II produced by lymph node cells are associated with pathology in collagen-induced arthritis in rats.

The relationship between the affinity of antibodies against type II collagen (CII) and arthritis was studied in rats immunized intradermally with bovine CII. Disease was associated with a higher mean titre of serum antibody and a lower mean functional antibody affinity (determined in a chaotropic dissociation assay) against both the immunizing bovine CII and homologous autoantigenic rat CII in comparison with the response in immunized rats that did not develop disease. The functional affinity of the antibodies present in the serum was found to correlate with that of antibodies produced in culture by cells from the lymph nodes draining the site of immunization with collagen. The reduction in mean functional affinity in the anti-collagen response may be the result of the increased production of antibodies of the lowest affinity and a consequent broadening of the affinity heterogeneity. It is proposed that production of low-affinity antibodies in the lymph nodes draining the site of immunization with collagen is important in the pathogenesis of collagen-induced arthritis in rats.